V929 Transmitter (without a working top-right button)
At 100%, it does not flip. There is no way to flip the quad.
V939 Transmitter (with a working top-right button)
At 100%, it does not flip. The only way to flip the quad is to press and hold the top-right button and apply full stick movements.
At 60%, holding the top-right button, and apply full stick movements, the quad flips.
As you hold on to the top-right button, keeping full stick movements will flip the quad consecutively. There are no pauses in between. At a height of 3 storeys, the quad will smash into the ground after 3 flips. It occurs really quick and real easy. You need to let go of the button or put the stick back to neutral once the flip begins, else, the next one will follow.
V949 Transmitter (with a working top-right button)
Contrary to the manual, it does not flip at 60% while holding on to the top-right button! Flips are only possible at 100% while holding on to that button.
Consecutive flips are harder to execute. Somehow, I had to hold on to the button, move the stick back and forth, to trigger the next flip. It is certainly unlike the V939.
V949 Transmitter paired with V929
At 100%, the V929 flips when the stick is moved fully. It was very sensitive but I don't remember if it was as sensitive as 100% on the V929 transmitter (I hardly fly at 100% to avoid accidental flips). At 60% on the V949 transmitter, the V929 feels significantly
more sensitive than when it was paired up with the V949. I couldn't tell if 60% on the V949 transmitter meant 80% on the V929 transmitter; or the V949 board interpretes 60% as 50%, but the fact is the V929 was very sensitive at 60%. This can be evidently demonstrated when executing piros - V929 piros faster than the V949 at 60%. I did not test V929 transmitter with the V949 specifically on the flight characteristics. Maybe next time.
At 40%, it felt similar to 40% on the V929 transmitter.
Based on my experiences above, it appears that the V949 board is more than just a V929 board with LED sockets.